Problem: $ { \left[\begin{array}{rr}{2} & {2} \\ {3} & {4} \\ {1} & {1}\end{array}\right]-\left[\begin{array}{rr}{2} & {-1} \\ {2} & {-1} \\ {1} & {4}\end{array}\right] = {?} } $
Explanation: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{2}-{2} & {2}-{-1} \\ {3}-{2} & {4}-{-1} \\ {1}-{1} & {1}-{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {3} \\ {1} & {5} \\ {0} & {-3}\end{array}\right]}$